Designation A1093/A1093M − 15 Standard Specification for Electrolytic Plasma Treatment Processing of Conductive Materials1 This standard is issued under the fixed designation A1093/A1093M; the number[.]
Trang 1Designation: A1093/A1093M−15
Standard Specification for
Electrolytic Plasma Treatment Processing of Conductive
Materials1
This standard is issued under the fixed designation A1093/A1093M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last
reapproval A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1 Scope
1.1 This specification covers the requirements for cleaning,
coating, or surface modification, or combinations thereof, of
conductive materials, primarily metals
1.2 This specification covers any conductive material
treated or processed by the electrolytic plasma process (EPP)
including: products designated as long products, including wire
and fine wire; flat-rolled materials; fasteners; connectors; bolts;
assemblies; structural materials; hardware items; and medical
items
1.3 Products created under this process shall specifically
specify requirements for the specific product being processed
using the EPP process
1.4 This specification is applicable for orders in either
inch-pound or SI units
1.5 The values stated in either SI units or inch-pound units
are to be regarded separately as standard The values stated in
each system may not be exact equivalents; therefore, each
system shall be used independently of the other Combining
values from the two systems may result in non-conformance
with the standard
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use It is the
responsibility of the user of this standard to establish
appro-priate safety and health practices and determine the
applica-bility of regulatory limitations prior to use.
2 Referenced Documents
2.1 ASTM Standards:2
A90/A90MTest Method for Weight [Mass] of Coating on
Iron and Steel Articles with Zinc or Zinc-Alloy Coatings
A924/A924MSpecification for General Requirements for Steel Sheet, Metallic-Coated by the Hot-Dip Process
Coating Thickness by Microscopical Examination of Cross Section
D2200Practice for Use of Pictorial Surface Preparation Standards and Guides for Painting Steel Surfaces
F519Test Method for Mechanical Hydrogen Embrittlement Evaluation of Plating/Coating Processes and Service En-vironments
2.2 SSPC Standard:3
SSPC-VIS 1Guide and Reference Photographs for Steel Surfaces Prepared by Dry Abrasive
3 Terminology
3.1 Definitions of Terms Specific to This Standard: 3.1.1 anode, n—positively charged device within the plasma
reactor
3.1.2 applied potential, n—direct current (dc) voltage
ap-plied between two electrodes, anode and cathode
3.1.3 aqueous plasma, n—use of water as the source of the
H2– H++ H++ 2e
3.1.4 cathode, n—negatively charged work piece within the
plasma reactor
3.1.5 electrolyte, n—aqueous solution containing ions
ca-pable of conducting electric current
3.1.6 micro-roughness, n—features formed as a result of the
kinetic energy produced from the implosion and rapid quench-ing phenomenon that occur durquench-ing electro-plasma technology (EPT) processing
3.1.7 plasma, n—collection of free moving electrons and
ions capable of conducting electric current
3.1.7.1 Discussion—In this case, the gas is hydrogen and the
ion is H+ Energy is required to make plasma Without sustaining energy, plasma recombines into molecular hydrogen, H+
1 This test method is under the jurisdiction of ASTM Committee A05 on
Metallic-Coated Iron and Steel Products and is the direct responsibility of
Subcommittee A05.12 on Wire Specifications.
Current edition approved Oct 1, 2015 Published November 2015 DOI:
10.1520/A1093A1093M-15.
2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 Available from the Society for Protective Coatings, 40 24th St., 6th Floor, Pittsburgh, PA 15222.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 United States
Trang 23.1.8 plasma reactor, n—device housing that confines the
plasma within the work zone containing the electrolyte, which
allows the formation of plasma
3.1.9 salts, n—refers to the soluble metal salts used within
the aqueous plasma process
3.1.10 surface morphology, n—unique surface characterized
by the presence of micro-craters and spheroids created by the
electro-plasma process
3.2 Acronyms:
3.2.1 EPP—Electro-plasma processing
3.2.2 EPT—Electro-plasma technology
4 Electro-Plasma Process (EPP) 4
4.1 Electro-plasma processes (EPP) are a hybrid of
conven-tional electrolysis and atmospheric plasma processes All the
independent studies lead to a common observation that, at a
certain value of voltage between two electrodes in an aqueous
electrolyte, will lead to deviation from Faraday’s normal
electrolytic regime Applied voltage is significantly greater
when compared to the conventional electrolysis leading to the
analogous phenomenon that is accompanied by the formation
of a continuous plasma envelope around either the cathode or
the anode with the presence of luminous discharge or glow
plasma The critical factors that influence the formation of the
continuous plasma envelope include applied potential,
electro-lyte temperature, geometry of the electrodes, nature and
properties of the electrolyte, and flow dynamics of the
electro-lyte and work piece Most of the studies are concentrated on
the anodic regime
N OTE 1—In the EPT process described here, the work piece is the
cathode and it is negatively charged Plasma forms on the cathode The
anode is the positively charged electrode.
Electro-plasma technology (EPT) is used to engineer metal
surfaces in the cathodic regime, but it can be used in the anodic
regime depending on desired results EPT processing is a
dynamic process that involves delivery of aqueous electrolyte
into a confined chamber (EPT reactors) on the surface of the
work piece Balance between electrolyte flow and plasma
generations ensures a uniform treatment of the metal surfaces
4.2 EPP is an environmentally friendly technology applied
in a closed-loop system
N OTE 2—There are no solid wastes generated from EPT Vapor
generated during the process can be captured and returned.
5.1 In a cathodic regime with an electrolyte of near neutral
salts, cleaning of a metal surface can be achieved EPT can
effectively remove lubricants, dirt, metal oxide scale, and so
forth from metal surfaces Organic materials are disassociated
into their gaseous components, thick oxides are broken and blasted off the surface, and thin residual oxide layers are reduced back to their pure metallic element
5.2 EPT cleaning uses thermal shock, electrical current, chemical reaction, and kinetic energy in the form of cavitation 5.3 Plasma formed on the surface of the work piece in a liquid electrolyte results in unique surface characteristics and a unique morphology (micro-roughness)
6 Electro-Plasma Cleaning Process
6.1 Electro-plasma cleaning of a continuous length of a conductive metal is accomplished by passing the item through
an appropriately designed reaction chamber The number of reactors required is speed-dependent and they are run in tandem
6.2 The reactor chamber is supplied with electrolyte in a controlled method
6.3 A large potential is set between the anode and cathode (work piece), normally in the range of 25 to 250 V
6.4 Luminous plasma is generated at the work piece surface and the work piece is cleaned of contaminants and oxides 6.5 The work piece then passes through a hot (70 ~ 80°C [160 ~180°F]) water spray rinse and is dried
6.6 The product can now be collected on a typical package
or it can go directly into EPT deposit reactors for coating with
a variety of metals and alloys
7 Testing Requirements: Cleaning
7.1 The degree of cleaning is typical for a specific industry but is typically done by comparing the appearance of the dirty component to the cleaned component and, therefore, is an attribute rating In this case, it is recommended that the surface
be examined under a magnification of 20× for signs of residual lubricant, soils, and oxides A minimum of at least three areas should be observed and the estimate of cleanliness recorded A rating is developed by estimating the percent of the field that contains no signs of residual lubricant, soils, or oxides The average of these estimate observations are recorded and used to rate the level of cleanliness The actual cleanliness level of a specimen may vary widely and still be acceptable for the intended end use The user will be responsible for determining the minimum level of their particular application It has been the experience when using EPT that the surface is 99 to 100 % free of any visual contamination
8 Electro-Plasma Deposition
8.1 EPT has the ability to deposit metal and alloy coatings such as zinc, nickel, zinc-nickel, nickel-copper, molybdenum, tin, and so forth EPT coatings exhibit excellent adhesion with the substrate and are deposited at significantly high deposition rates as compared to conventional electrolytic processes EPT has also been used to alloy metals such as molybdenum onto
4 The electrolytic plasma process, Patent number US 6585875 is covered by a
patent Interested parties are invited to submit information regarding the
identifica-tion of an alternative(s) to this patented item to the ASTM Internaidentifica-tional
Headquar-ters Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend.
ASTM International takes no position respecting the validity of any patent rights
asserted in connection with any item mentioned in this standard Users of this
standard are expressly advised that determination of the validity of any such patent
rights, and the risk of infringement of such rights, are entirely their own
responsibility.
Trang 3another metal’s surface The science of electro-plasma
deposi-tion is reviewed in the publicadeposi-tion “Electro-Plasma
Technol-ogy: Science and Engineering – An Overview.”5EPT
deposi-tion does not follow typical electro-plating principles The
transport of ions from the electrolyte to the cathode is not
limited by what is known as the boundary layer In EPT the
metallic ions are transported on plasma bubbles and, in simple
terms, hurled at exceptionally high velocities to the cathode
This accounts for the higher deposition rates compared to
normal electro-plating rates and eliminates the phase boundary
diffusion layer that limits the rates in conventional systems
9 Electro-Plasma Deposition Process
9.1 Electro-plasma deposition of a continuous length of a
conductive metal is accomplished by passing the item through
an appropriately designed reactor chamber The number of
reactors required is dependent upon speed and the thickness of
deposit desired, and they are run in series Deposits can be
made as a single layer of a mono-metal or an alloy Deposits
can also be in separate and distinct layers of different metals
Very thin layers of some metals can be alloyed with the surface
of the substrate such as molybdenum
9.2 The reactor chamber is supplied with electrolytes
con-taining the metal ions to be deposited and supplied in a
controlled method
9.3 A large potential is set between the anode and cathode
(work piece), normally in the range of 25 to 250 V (In EPT,
Faraday’s law does not apply as with normal electro-plating
processes.)
9.4 Luminous plasma is generated at the work piece and the
wire or other work piece is coated with the metal ions
contained in the electrolyte
9.5 The work piece then passes through a hot (70 ~ 80°C
[160 ~180°F]) water spray rinse and is dried
9.6 The product can now be collected on a typical package
or it can go directly into a second set of deposition reactors for
coating another metal
9.7 The last step is to rinse the coated product with hot
water and dry before packaging
9.8 Intermetallic—With EPT deposition, there is no
inter-metallic zone created
9.9 Mechanical properties such as tensile strength and
torsion will not change because of the process EPT also will
not cause any hydrogen embrittlement The process parameters
should be controlled to make sure that the work piece is not
overheated during the process The tensile test data for
as-drawn compared to as-EPT-zinc-coated and as-EPT-cleaned
wire shows that the tensile strength is not changed Tests
according to Test Method F519 have shown that the EPT
process does not cause hydrogen embrittlement
10 Testing Requirements: Coating
10.1 Testing is highly dependent on the user requirements
10.2 Adhesion—The coating shall show no signs of flaking
when the samples are bent or twisted as described in the following:
10.2.1 Round—Wraps should be made around mandrel of
the same diameter as the test sample (minimum of five turns) and examined under 10× magnification
10.2.2 Wire—To determine ductility and coating adhesion,
wire can be wrapped around its own diameter, five wraps on without breaking of the wire or delamination of the coating
10.2.3 Sheet—A 180° bend examined under 10×
magnifica-tion
10.3 Ductility—The coated samples shall be broken in
tension and the fracture observed at 10× magnification, and the coating will show ductile flow to point of fracture without separation between coating and substrate
10.4 Thickness—The specific thickness shall be agreed
be-tween the purchaser and manufacturer The following methods may be used to verify the average thickness
10.4.1 Electrical Permeability—Using a standard of known
thickness of the same coating material can provide a relative measurement
10.4.2 X-Ray Diffraction—Using a standard of known
thick-ness of the same coating material can provide a relative measurement
10.4.3 Metallographic Measurement—Test MethodB487 A sample can be prepared in cross section, polished, and viewed
at an appropriate magnification to allow microscopic measure-ment of the perpendicular thickness of the coating A minimum
of three points spaced around the cross section evenly but including thicker and thinner spots to arrive at an average thickness
10.4.4 Weight Measurement by Stripping the Coating—Test
Method A90/A90M Selecting a sample of appropriate size, normally 5 to 20 g, and the initial weight is recorded The coating is dissolved with the appropriate chemical agent The sample is rinsed in deionized (DI) water and dipped in acetone and allowed to dry Reweigh the sample and record the new weight Using the density of the coating material, calculate the average thickness on the cross section
11 Coating Properties
11.1 Coating Weight (Mass)—Use the following
relation-ships to estimate the coating thickness from the coating weight for zinc (mass):
1 oz⁄ft 2 weight 5 1.7 mil coating thickness (1) and
17.14 g⁄m 2 weight 5 1 µ coating thickness (2) where:
1 oz/ft2 = 305.15 g/m2
11.2 Coating Weight (Mass) Tests
11.2.1 Coating weight (mass) tests shall be performed in accordance with the requirements of Specification A924/ A924M
5 Gupta, P., G Tenhundfeld, E.O Daigle, and D Ryabkov “Electro-Plasma
Technology: Science and Engineering – An Overview,” Surface and Coatings
Technology, Vol 201, No 21 2007; p 8746–8760.
Trang 411.2.2 The referee method to be used shall be Test Method
A90/A90M
11.3 Coating Bend Test—Any bend with tension on the
outside surface that does not cause fracture of the base metal
can be performed with the EPT coatings to reveal the potential
delamination, cracking, or peeling of the coating
11.3.1 The bend test specimens of coated sheet or bar
designated by prefix “G” (“Z”) shall be capable of being bent
through 180° in any direction without flaking of the coating on
the tension side of the bend only Flaking of the coating within
6 mm [0.25 in.] of the edge of the bend specimen shall not be
cause for rejection
11.4 Corrosion—The customer and supplier should agree on
the corrosion properties
11.4.1 Wire Products—The coated rod or wire can be drawn
to the maximum limit possible within the properties of the
original material
11.4.2 Since no coating is lost during drawing, the final
coating thickness will depend on the starting coating thickness
and the total diameter reduction during drawing The amount
of coating on the finished product should be agreed between
the supplier and customer
11.5 Appearance—The coating should be continuous and
reasonably uniform It should be free of any imperfection
12 Surface Modification/Cleaning Characteristics
12.1 The surface of the work piece will have unique
characteristics because of the plasma process This is identified
by “spheroids” and “craters” that are created on the surface
The size and distribution of these characteristics can be
changed by altering the process parameters that includes
voltage and electrolyte properties
13 Coating Weight and Thickness
13.1 The coating weight and thickness for the final product
should be agreed upon between the customer and
manufac-turer
14 Coating Characteristics
14.1 The coating deposited by EPT is free of any
interme-tallic layers For example, in the case of zinc coatings, only
pure zinc is present in the coating (seeFig 1andFig 2) No
zinc-iron intermetallic layers are present in the coating
14.2 Steel chemistry does not have any influence on the
coating properties
14.3 The coating is adhered to the substrate by a
metallur-gical bond that is formed because of the action of plasma
15 Retests and Disposition of Nonconforming Material
15.1 Retests, conducted in accordance with the
require-ments of the section on retests and disposition of
nonconform-ing material of Specification A924/A924M, are permitted
when an unsatisfactory test result is suspected to be the
consequence of the test method procedure
15.2 Disposition of nonconforming material shall be subject
to the requirements of 9.2 of SpecificationA924/A924M
16 Dimensions and Permissible Variations
16.1 All dimensions and permissible variations shall com-ply with the requirements of SpecificationA924/A924M
17 Sampling
17.1 Test specimens shall be selected randomly from each inspection lot
17.2 The method of selection and sample size shall be agreed upon between the processor and the purchaser Testing requirements shall determine the test specimen size
18 Specimen Preparation
18.1 Test specimens shall be prepared in such a manner as
to meet the necessary testing standards required to meet the purchaser’s requirements for cleaning and coating
18.2 Cleaning shall be determined by the percentage of the contaminant found to remain on the processed sample, includ-ing oxide scale Oxygen content should not be used since time and atmosphere can cause abnormal readings
19 Test Methods
19.1 Cleaned samples can be observed under an optical microscope or scanning electronic microscope (SEM) to deter-mine the level of cleanliness
19.2 SSPC-VIS-1 can be used as a visual standard to determine the level of cleaning; however, the starting condition
FIG 1 Tensile Test Data Comparing As-Drawn, EPT Zinc-Coated, EPT Cleaned, and Hot Dip Galvanized Zinc-Coated Wire
Trang 5of the material to be cleaned has to be noted This standard
conforms to Practice D2200
20 Certification
20.1 When specified by the purchaser or within the contract,
the processor shall submit test specimens and reports for each
specimen to the purchaser The purchaser shall have to the
option to accept the processor’s reports or request additional
test specimens for certification, in which case, the purchaser is
obligated to pay for the cost for the additional testing and
reporting
21 Packaging
21.1 The purchaser shall specify packaging requirements at the time of placing the order, otherwise, the processor shall use
a best practices for the product to be packaged
22 Keywords
22.1 cleaning; coatings zinc; electro-plasma; steel products-metallic coated; steel wire; zinc-nickel
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FIG 2 Photomicrograph of EPT Zinc Coating (×750) Showing that Only Zinc is Present in the Coating and Intermetallic Layers are
Absent